This invention relates to disposable single serve beverage filter cartridges.
A known disposable single serve beverage filter cartridge is disclosed in U.S. Pat. Nos. 5,325,765 and 5,840,189 (Sylvan et al), dated respectively Jul. 5, 1994 and Nov. 24, 1998. This beverage filter cartridge is comprised basically of an impermeable yieldably piercable cup-shaped container thermoformed or injection molded from a relatively rigid plastic material, and internally subdivided by a permeable cone-shaped filter into first and second chambers. A granular or powered dry beverage medium, e.g., roasted ground coffee, is stored in the first chamber, and the container is closed by an impermeable yieldably piercable lid comprising a laminate of metallic foil and plastic.
During a brewing cycle, the lid and container bottom are pierced from opposite directions, respectively, by tubular inlet and outlet probes. The inlet probe admits heated liquid into the first chamber for infusion with the beverage medium, and the resulting brewed beverage passes through the filter into the second chamber from which it exits via the outlet probe for delivery to an underlying cup.
This known beverage filter cartridge has gained rapid and increasingly widespread acceptance, notwithstanding certain problems and disadvantages relating to its use that have persisted since its initial introduction.
For example, as compared to the lid, the bottom of the cup-shaped container is relatively thick, with a higher resistance to piercing. The bottom cannot easily be thinned without adversely affecting the required thickness of the cup""s sidewall to prevent permeability to oxygen and the ability to connect the filter material to the sidewall without damaging the oxygen barrier material. Thus, in the course of being punctured by the outlet probe, the bottom exhibits a tendency to distort inwardly, with an accompanying buckling of the container sidewall. Bottom distortion accompanied by sidewall buckling can adversely affect the puncturing process, resulting in leakage around the outlet probe.
A related problem stems from the need to equip the brewers with expensive metallic outlet probes that can be sharpened to the extent necessary to effect piercing of the more resistant container bottoms, and that can resist wear over prolonged periods of use.
Additionally, some of the brewed liquid beverage is not able to be evacuated because the outlet probe opening is above the bottom of the container and some of the beverage has no means of drainage.
What is needed, therefore, is an improved beverage filter cartridge that obviates or at least significantly minimizes the above-noted problems and disadvantages.
In accordance with the present invention, a beverage filter cartridge includes an impermeable outer container having an access opening. A planar filter element is configured and arranged to subdivide the container interior into first and second chambers. A beverage medium is stored in the first chamber and an impermeable lid closes the access opening.
The lid has a first section overlying the first chamber and a second section overlying the second chamber. The first and second lid sections are yieldably piercable, respectively, from the same direction, by single or multiple inlet and outlet probes. The inlet probe admits heated liquid into the first chamber for infusion with the beverage medium, and the resulting brewed beverage passes through the filter element into the second chamber, from which it exits via the outlet probe.
The lid material has a lesser resistance to being yieldably pierced as compared to the resistance of the container bottom, and is thus less prone to inward distortion with accompanying buckling of the container sidewall. The net result is a cleaner puncture and in improved seal around the outlet probe.
The relative ease with which the lid may be pierced also makes it possible to equip tie brewers with less expensive plastic inlet and outlet probes, in single or multiple configurations.
These and other features and advantages of the present invention will now be described in greater detail with reference to the accompanying drawings, wherein: